Up until now, and as shown in U.S. Pat. No. 4,851,019, two guide cams dip into the engaging recesses of the base plate of a filter bag when the intermediate carrier for the filter bag is closed. In this way, it is ensured that the stub mounted on the intermediate carrier dips centrally into the filter bag. However, the guide cams alone cannot prevent filter bags from being used which are not designed specifically for the apparatus; that is, filter bags which do not have engaging recesses through which the guide cams can slide.
Resistance is offered to the guide cams by a base plate of an unauthorized filter bag which does not have the engaging recesses. This resistance can be overcome by the application of intense pressure when closing the filter cassette.
In this way, the vacuum cleaner can be operated with filter bags which are mounted incorrectly because they are not designed specifically for the apparatus.
This causes the filter bags to be improperly filled which means that more filter bags are needed over an extended period of time than would be the case where there is an optimal filling of the filter bags specific to the apparatus.
This leads to a greater burden to the environment and is of greater monetary cost to the consumer.
In addition, dust can reach the ambient in the case of a poorly seated filter bag and this disables special filters for filtering the fine dust and has negative health consequences for the operator and especially an operator allergic to household dust.